Re: AccidentalCautionary in NullVoice

[Keith OHara]

On Sat, 23 Aug 2014 13:16:22 -0700, Dan Eble <address@hidden> wrote:

> On Aug 23, 2014, at 08:03 , Dan Eble <address@hidden> wrote:
>
> I think I’m really close (again!) to getting modern-voice-cautionary 
> accidentals with combined-part stems by defining a new accidental style that 
> disregards the part combiner’s voices.

It looks to me like make-limited-accidental-rule limits the creation of 
accidentals to a particular context, but it seems the accidental engraver would 
still consider the history of pitches recently seen throughout the staff.

Each context Staff, Voice, your previous SpecialVoiceGroup,  keeps track of 
accidentals in a data structure called localAlterations.  You might need to 
initialize it with \set SpecialVoiceGroup.localAlterations = #'()

Your previous approach with the SpecialVoiceGroup seemed more promising, if 
that group includes only the separate voices for each part, and if you move the 
accidental_engraver to that group.

> It appears that in some cases both a cautionary and a normal accidental are 
> typeset.  If just the normal accidentals were typeset, the output of the 
> following example would be exactly what I want.  Is this a bug?

In your latest code, the interaction between contexts and the setter routines 
is complicated, but as I understand it, the partcombine voices are still 
producing accidentals following the portion of the rule that was not restricted 
to NullVoice.  That portion includes a rule to produce Cautionaries, but no 
rule for normal Accidentals.  Those voices, made by partcombine, produce the 
cautionary (in black) because those voices didn't produce any normal 
accidentals.